This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Studies suggest that early treatment of infants diagnosed with an inherited disease provides the best survival and clinical outcomes, and that immature cell sources may be most efficient for transplant. Progress in the stem cell field has been hampered by difficulties in finding predictive models that permit in vivo analysis of human cells. These studies will explore the fate of transplanted human cells from two differing sources. They will have important outcomes towards overcoming bottlenecks by addressing essential issues related to human pluripotent cells for clinical transplantation and conduct proof-of-principle translational studies for humans.